Timer brush



A. w. CAPS.

TIMER BRUSH.

APPLICATION FILED MAY 24, 1920.

1,4;38Q425, Patented Dec. 12,1922.

I '24 NAM- 4 A a lNVE/VTOR 7/7/1 Wap-s A TTORNE Y Patented Dec. 12,1922.

UNITED STATES PATENT OFFICE.

ARTHUR W. CAPS, OF TOPEKA, KANSAS, ASSIGNQR, BY MESNE ASSIGNMENTS, TO 0.I).

COLLIS, OF CLINTON, IOWA. v

TIMER BRUSH.

Application filed May 24,

T all whom it may concern Be it known that I, ARTHUR IV. CAPS, a citizenof the United States, residin at Topeka, in the county of Shawnee andtate of Kansas, have invented certain new and useful Improvements inTimer Brushes; and

I do declare the following to be a full, clear,

and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same,reference being had to the accompanying drawings, and to the letters andfigures of reference marked thereon, which form a part of thisspecification.

This invention relates to electric timers for the ignition system of anexplosion engine and, specifically, it has reference to a novelconstruction of timer brush for use in a timer casing.

Electric timers usually consist generally of a casing provided with acommutator consisting of spaced and insulated contacts 00- operatingwith a rotatable brush to intermittently make and break the timercircuit. The insulation and contacts are usually constructed to form aring-shaped commutator, over which a rotatable timer brush travels, andthe interior of the casing isusually packed with grease in order toinsure lubrication to assist in the smooth co-operation of the parts.Sometimes dust collects in the casing, or the grease dries out, and as aresult the rotatable brush packs the dust and grease over the surface ofthe commutator, forming a hard, gummy film and thus seriouslyinterfering with the perfect timing of the making and breaking of thecircuit.

My invention contemplates the provision of .an electric timer in whichthe brush is in the form of a wiping contact, which passes over thecommutator surface in such a manner that it will wipe off anyaccumulating grease or dirt, leaving the surface of the commutatorbright and clean sothat a perfeet operation of the timer may be insured.I prefer to maintain the wiping cont-act or brush under tension so thatit wili bear against the face of the commutator over which it travels toinsure the removal of any accumulations and so that there will beanintimate contact between the brush and the commutators surface at alltimes.

The construction of the brush and commutator is such that the engine mayback- 1920. Serial N0. 383,694.

fire and thereby reverse the direction of movement of the brush withoutdanger.

The construction selected for illustrative purposes in order toexemplify the novel features of my invention constitutes only one formof the device, it being apparent that the specific construction may bevaried without, departing from the generic conception thereof.

In the drawings:

Fig. I is a perspective view of a brush and its bracket, disassociatedfrom the timer shaftQ Fig. II is a cross sectional view through thetimer casing, the commutator, brush, bracket and shaft being shown inend elevation, and

Fig. III is a cross sectional view on the line III-III of Fig. II.

The particular construction of the timer casing and the commutatorconstitutes no part of this particular invention but I have shown acasing 1 provided with a commutator consisting of the insulationsegments 2 and the inserted contacts 3, one for each spark plug of afour cylinder engine and. spaced equi-distantly about the commutator.The insulation segments 2 and the inserts 3 constitute a commutator ofcircular form so that the inner face 4 of the.

commutator over which the brush travels is annular. Concentric with theannular commutator is a timer shaft 5, which may be driven in any wellknown manner.

The timer shaft is adapted to receive a brush bracket consisting of atubular memher 6, preferably of spring metal and normally of lessdiameter than the diameter of the shaft. The tube is slitlongitudinally, as at 7, so that it may be expanded to embrace the shaft5 and when released, will clamp upon the shaft 5 to be in intimatecontact therewith:

In order to prevent rotative movement of the tube 6 with respect to theshaft 5, I have provided the tube with a longitudinal notch or slot 8,adapted to receive a pin or lug 9 on the shaft 5 when the tube issleeved on said shaft. One edge of the tube at the slitted portion 7 isprovided with an outstanding fiange 10, having perforations 11 and 12 toreceive the hooked ends 13 and 14: of the spring arms 15 and 16 whichcarry the brush element, the arms being connected at their outer ends bya bar member 17, which passes through a bore 18 in the brush element 19.The brush element 19 is preferably grooved at its respective ends, asindicated at 20 and 21. to receive the arms 15 and 16, which hold it innon-rotative position so as to eliminate liability of the brush element. 19 rotating on the bar or shaft 17, which it would otherwise dobecause the brush element 19 is shown as a cylinder.

The arms 15 and 16 pass through the openings 22 and 23 in theoutstanding flange 24, struck up from the tube 6, the flange 2i and theflange 10 constituting eflicient anchorages for the brush supportingloop consisting of the arms 15 and 16 and the bar 17.

I prefer to form the arms 15 and 16 of the brush supporting loop uponarcs of greater radii than the radius of the commutator so that when theparts are assembled, as shown in Fig. II, the arms will be bentinwardly, but since they are of spring metal and will tend to springback into their original shape, it will be apparent that the arms willbe put under tension when the parts are assembled and, therefore, thebrush 7 will be held in intimate contact with the commutator surface 4at all times.

If the parts are in the position shown in Figs. II and III and the timershaft 5 is rotating in a contra-clockwise direction the brush 19 will beunder tension against the surface or face 4 of the commutator and serveas a wiping contact non-rotatable about its axis. Therefore, liabilityof a film of grease or dirt being packed upon the surface 4 of thecommutator will be eliminated.

On the other hand, the surface will be kept free from accumulations andthe ,eflicient performance of the timer insured.

Should the engine back-fire so as to drive the shaft 5 clockwise, thecontact would sim ply reverse its direction of movement without imparingthe mechanism of the timer in any way, this being a material advantagein timer construction.

It is also an important feature of my invention that the supporting loopconsisting of the arms 15 and 16 is so curved that the timer may beoperated in either direction if necessary. 7

hat I claim and desire to secure by Let" ters-Patent is:

1. In an electric timer, a shaft engaging sleeve. flexible arms mountedon the sleeve, and a brush carried by said arms and having transversegrooves at its ends, seating said arms to prevent rotation of the brushwhen in contactwith a commutator.

2. In an electric timer, a shaft engaging sleeve, a brush having alongitudinal bore and transverse end grooves, and flexible arms carriedby the sleeve, and a member connecting the ends of said arms andextending through the longitudinal bore in the brush to support thebrush, the end portions of the arms being seated in the brush grooves tohold the same against rotation.

In testimony whereof I affix my signature.

.ARTHUR W. CAPS.

